基于速度环补偿的零力控制方法

Force-Free Control Method Based on Speed Loop Compensation

针对当前零力拖动控制方法成本较高、系统复杂的缺点,课题组提出一种基于速度环补偿的零力控制方法,适用于小型机械臂的拖动示教。根据伺服电机励磁电流与力矩的线性关系,利用电流检测代替复杂的力矩传感器,并通过实验验证这一替代的可行性;设计一种模拟人手拖动单关节电机实验方法,运用控制变量法研究在外力拖动下关节电机转速与励磁电流之间的关系。实验结果表明外力不变时存在一个转速使励磁电流值最小,此时对应了需要的拖动力最小。本研究验证了基于速度环进行零力控制的可行性,为零力控制提供了新的思路。

Aiming at the disadvantages of high cost and complex system of current force-free drag control methods,a force-free control method based on speed loop compensation,which is suitable for drag demonstration of small mechanical arms,was proposed.Based on the linear relationship between the excitation current of the servo motor and the torque,the current detection was used to replace the complex torque sensor,and the feasibility of this alternative was verified by experiments.An experimental method for simulating a single-joint motor that is dragged by a human hand was designed,and the controlled variable method was used to study the relationship between the joint motor speed and the excitation current under external force.The experimental results show that when the external force is constant,there is a speed to minimize the excitation current value,which corresponds to the minimum drag force.The feasibility of forcefree control method based on the speed loop is verified and a new idea for force-free control is provided.